Lots Road Power Station.

David St George

On arriving at the station, I was reminded of Ronnie Barker in "Porridge". There is a massive gate with a small door inset and on ringing the bell I was admitted and after stating who I was, I was shown (or escorted!) into a small guard house where I had to give all possible details and fill in a form. I was then given a pass 'to be worn at all times whilst on the premises'.

After a short while a very pleasant gentleman appeared and I was shown up two flights of stairs to an immaculate 'chemi lab' which my guide explained was a very necessary part of the station. (He was a chemist by profession.) From this pristine atmosphere I was escorted through a long passage to the heart of the station. Here things were very different, noisy and dirty! Looking down into the generator hall was like looking into a large cathedral with the alternators lined up neatly in a row. Lots Road Power Station provided, together with Greenwich power station, the motive force of the London Underground.

There is an ancient rumbling lift which took us to various stages including the boilers (gas fired) and the switch room. From the roof I can see Chelsea's football ground and a large distance up and down the Thames. When the District Railway acquired the power station site in 1902/3 the houses on the north side of Lots Road had already been built. In 1901 James R. Chapman, chief engineer to the MDET Co. who had come from America with Yerkes, invited tenders for the supply and installation of plant at Lots Road. The Westinghouse Electric Manufacturing Co. of Pittsburgh was invited to tender for four 7000 HP compound engines and The British Westinghouse Co. for four 5,000 kW, 11,000 volt, 25 Herz alternators.

A letter of intent to purchase four steam turbines with four alternators for £152,000 was issued in August 1901. This was subject to arbitration over the system of electrification to be adopted jointly for the Circle Line. The decision in favour of the D.C. system as opposed to the GANZ three-phase overhead conductor system was given in December 1901. However the capacity of the generating station would have to be increased to 40,000Kwts to provide for the requirements of the three tube railways beside the District Railway. The contract was therefore placed for eight steam turbine alternators each having a nominal output of 5,500 kW and operating at 1,000 RPM to give a frequency of 33.3 Hz (as compared with 5,000 Kw and 25 Hz originally specified). Construction work began in 1902.

The first through trip from Mill Hill Park to Bow Road and back was made on the 28th March 1905. On the 13th June 1905 a public service was operated from South Acton through Mill Hill Park to Hounslow and from that date the District Railway began to depend on the output from Lots Road. Steam locomotives continued on the Inner Circle until 23rd September and almost all steam trains were withdrawn from the District Railway by 5th November 1905. Only four machines were available for the June 1905 railway service although a fifth set became available in July. The last of the eight units contracted was in service in May 1906. Numerous problems arose with vibration and erratic governing, with failures of the automatic stop valves, the circulating water pump drives and the vacuum pumps. In early 1905 - before commercial operation had started - Yerkes was complaining to Geo. Westinghouse that he was receiving threats of legal action from owners of the neighbouring properties because of the noise and vibration. On the 10th March 1905 Westinghouse replied that "every possible effort will be made to hasten forward the needed changes. No one however is better aware than you are, how much time is consumed in England in doing even ordinary work". Alterations to the enclosures of the alternators were made in 1906 with satisfactory results on both temperatures and noise, although there was still doubt about the machines meeting the specified 50% overload.

A contract with C.A. Parsons & Co., dated 31st December 1908, provided for the installation of four steam turbines to drive four of the existing alternators, with the resulting sets having a rating of 6,000 kW. A second contract followed for four further units and all the Westinghouse turbines had been replaced by 1910. The contract price for each turbine was £8,100, which may be compared with the original Westinghouse tender price of £31,000, although this had been reduced in subsequent negotiations. The load on the generating station increased as the tube lines were opened. The Baker St and Waterloo Railway was opened on March 10th 1906 between Baker Street and Kennington Road and was extended to Elephant and Castle on August 5th 1906 and to Edgware Road during 1907.

The general strike of 1926, when the power station was manned by naval personnel, had drawn attention to the risk of the underground associated with its independent power supply system at a non-standard frequency. The extensions to Morden and Cockfosters had already been supplied from public supply undertakings at 50Hz. After the formation of the London Passenger Transport Board in 1933, the need to co-ordinate the separate power supply systems of the constituent undertakings was recognised and it was decided that the standard supply frequency of 50Hz should be eventually adopted.

The 1939/1940 New Works programme included the first stages of modernisation at Greenwich and Neasden Generating Stations, and the provision of a link between Lots Road and Neasden by connecting transformers installed at both stations with 22,000 volt cables. This was during the Second World War, and apart from numerous incendiary bombs there was only one direct hit on the station, although there were many in the surrounding streets. A bomb was also reported to have fallen in the Creek and a splash of mud was found on the south wall. As happened elsewhere, women were recruited to the staff as Fitter's Mates and Cleaners, including boiler cleaner! But it seems that the only woman on the Operations Staff was a control room assistant.

It had been assumed in various modernisation reports that Lots Road would continue to be coal fired, but post-war the use of heavy fuel oil in power stations had been developed to provide an economic alternative. This had the advantage of not requiring such complex and costly fuel handling plant, which would have been very difficult to accommodate on such a congested site. Work started at Lots Road in 1963 at the west end of the site. The first boiler and turbine were commissioned in July 1965. This was the first Membrane Wall boiler to be commissioned in this country, the second boiler and turbine followed shortly. Many of the substations fed from Lots Road at 33.3 Hz had been prepared for the change of frequency by diverting one of a pair of high voltage feeders to Cromwell Curve or Coburg Street so that part of the load could be transferred to the 50 Hz system almost immediately, followed by a phased programme to build up the load on Lots Road within the 30 MW firm capacity.

Deliveries of coal by rail ceased in 1965, and the Lots Road modernisation programme was completed in 1969 resulting in the power system being supplied from two sources independent of the National Grid for the Underground sections and from a bulk supply on the grid at Neasden for the surface section, in accordance with the recommendations of the 1960 report.

The boilers at Lots Road had been designed to burn heavy fuel oil with a sulphur content not exceeding 1% to limit the emission of sulphur dioxide. This was relatively cheap at that time as the quantity of H.F.O. produced by the oil industry was linked to the demand for petrol and diesel fuel rather than to the market for fuel oil. Natural gas from the newly discovered North Sea gas field was made available in 1974, initially at Greenwich but shortly afterwards at Lots Road. The GLC, now controlling London Transport, approved the conversion of both stations for dual fuel operation. The work was completed in 1977.

By 1980, the power supply system was again under review. The cost of electricity generated at Lots Road was found to be higher than that purchased from the Central Electricity Generating Board. The value of independent generation was no longer accepted, given the improvements in technology, in plant availability and inter-connection which had been introduced on the National Grid since the previous study twenty years before.

A Future Power Supplies project was drawn up which envisaged three dedicated Bulk Supply Points from the National Grid, any two of which would be capable of meeting the full load of the system and a last-resort emergency supply from the Greenwich gas turbines to feed essential lighting, ventilation pumps and communications. Approval in principle was given in 1985, and construction of the Mansell Street supply point and alterations to the 22,000 volt distribution system were well in hand when the Government announced its policy of de-nationalisation of the electricity supply industry.

The prospect arose of using the two sites for modern generating stations to feed into the local public supply network as well as continuing to supply the Underground. Further work on the Future Power Supplies project was suspended in 1990, while this was investigated by a joint venture between London Underground Ltd with Scottish Power plc and Veba Kraftwerke Ruhr AG. After the difficulties became more apparent, however, work on the Future Power Supplies project recommenced in 1992, on construction of the Lots Road intake and on planning the station and tunnel emergency lighting systems. It was envisaged that Lots Road would be closed in 1997 after completion of the schemes for emergency lighting and the refurbishment of five of the Greenwich gas-turbine units. But in March 1995 the department of Transport decided that private sector finance must be sought for these projects. This resulted in delays which lasted to the time of the visit, in spring 2002. Since then, Lots Road has finally been closed!

The Creek where warm water is exuded from the station is full of fish and the herons and other birds have a ready supply. The water for cooling is taken from a large filter structure protruding from midstream. I was very impressed with the control room with its switchboards and Apple computers. It is such a contrast with the grime down below in the boiler house.

Peter R Wallis

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Last updated by Julie Atkinson   28-Jan-2018